The Photophysics of Polythiophene Nanoparticles for Biological Applications
The Photophysics of Polythiophene Nanoparticles for Biological Applications
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DOI：
10.1002/cbic.201800167
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发表时间：
2019-02-15
期刊：
影响因子：
3.2
通讯作者：
Lanzani, Guglielmo
中科院分区：
文献类型：
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作者：
Bargigia, Ilaria;Zucchetti, Elena;Lanzani, Guglielmo
在这项工作中，我们从生物应用的角度研究了聚3-己基噻吩纳米粒(NPs)的光物理性质。纳米粒子以胶体悬浮液的形式存在于水溶液中，在低能区有明显的吸收带。根据对不同pH条件下的吸收光谱和瞬时吸收光谱的系统分析，该带与疏松结合的高分子链的极化产生的电荷转移态有关，并且起源于吸电子物种形成的络合物。重要的是，光激发时这些态的基态耗尽即使在微秒时间尺度上也是活跃的，因此表明它们是长寿命极化子的前驱状态；这可能有利于细胞刺激。细胞内NPs的初步瞬时吸收显微镜结果显示，存在长期存活的物种，进一步证实了它们与生物界面的相关性。
In this work the photophysics of poly(3-hexylthiophene) nanoparticles (NPs) is investigated in the context of their biological applications. The NPs, made as colloidal suspensions in aqueous buffers, present a distinct absorption band in the low-energy region. On the basis of systematic analysis of absorption and transient absorption (TA) spectra taken under different pH conditions, this band is associated with charge-transfer states generated by the polarization of loosely bound polymer chains and originating from complexes formed with electron-withdrawing species. Importantly, the ground-state depletion of these states upon photoexcitation is active even on microsecond timescales, thus suggesting that they act as precursor states for long-living polarons; this could be beneficial for cellular stimulation. Preliminary transient absorption microscopy results for NPs internalized within the cells reveal the presence of long-living species, further substantiating their relevance in biointerfaces.